Lucretius (lū̇-krē′shĭ-ŭs), Roman poet and philosopher of the 1st century B. C. Very little is known of his history, and his only work is a philosophy in poetry on Nature (De Rerum Natura). Lucretius was an earnest opponent of all religious faith and of all belief in supernatural power. The highest good to him is a calm and tranquil mind. The creation of the world out of nothing he held to be impossible, neither can anything be destroyed. Life, mind, soul are merely, as we should say, functions of the body and will perish with the body. All knowledge is derived from the senses, which are our only test of truth. There is a decidedly modern flavor about some of the doctrines of Lucretius. For instance: He explains contagious diseases by the flying about in the air of minute particles, germs as we call them, injurious to life; and again, in his account of the various types of animal life, as they have successively appeared on the earth, we almost have an anticipation of the Darwinian theory of evolution. He died by suicide in 55 B. C.